In 1987’s The Art of the Deal, Donald Trump, by way of ghostwriter Tony Schwartz, had this to say about his pugilistic nature. “[W]hen people treat me badly or unfairly or try to take advantage of me, my general attitude, all my life, has been to fight back very hard. The risk is you’ll make a bad situation worse, and I certainly don’t recommend this approach to everyone. But my experience is that if you’re fighting for something you believe in — even if it means alienating some people along the way — things usually work out for the best in the end.”

Or, as he put it on Wednesday when asked in a rollicking news conference if he would be able to work on bipartisan initiatives with Democrats if they pursue investigations into his administration: “If they do that, then it’s just — all it is, is a warlike posture.”

A critical turning point in the Trump presidency just arrived, and if he thought the Swamp was against him before, just wait until January. After taking over the House in Tuesday’s midterm elections, Democrats all of a sudden have leverage on legislation big and small. Perhaps more importantly, they have the power to subpoena documents and witnesses from the administration, as well as drive news coverage with high-profile hearings. Does Trump or his new interim attorney general want to fire Special Counsel Robert Mueller? Fine, the House Judiciary Committee will simply invite Mueller over to share his findings with every TV camera within a 30-mile radius.

And yet, this new dynamic suits Trump.

The Republican Congress has been mostly compliant, passing tax cuts while the House Intelligence Committee runs interference on the Mueller probe. But it’s created awkwardness when Trump doesn’t get his way, for example, on funding a wall at the border or the repeal of Obamacare. He’s comfortable taking shots at Paul Ryan, Bob Corker or the late John McCain, but the optics aren’t great. Remember the seminal moment of this year was when the entire GOP and conservative universe aligned with Brett Kavanaugh against Democrats and his accusers and installed him on the Supreme Court? Plan to see that dynamic play out again and again.

For the next two years, the Washington storylines will not be driven by Republican infighting, but by a clearly defined Democrat versus Republican battle. It all improves Trump’s chances for re-election in 2020. He’s better with a foil, and instead of ejecting reporters from the White House grounds, he can focus better on Democrats. (Though the mutually beneficial CNN fights will surely continue.)

Sure, Trump still has the capacity to surprise. He could swing left on a deal to spend $1 trillion on new roads and bridges or crack down more on the pharmaceutical industry. He’s expressed a fondness in the past for dealmaking with his pals “Chuck and Nancy,” who seem to understand his transactional nature.

But don’t bet on it.

The Democrats will start with carefully choreographed hearings and investigations of only the most egregious-seeming scandals — they’ve already requested records related to Attorney General Jeff Sessions’ ejection last week and the installation of Mueller critic Matt Whitaker over the special counsel probe. Speaker-in-waiting Nancy Pelosi has done her best to tamp down expectations of impeachment, but the pressure will only grow as 2019 gets underway. A Wall Street Journal report on Friday laying out federal prosecutors’ evidence of Trump likely breaking campaign finance law to pay off mistresses in 2016 will be more than enough for many Democrats to shout “high crimes and misdemeanors.”

The political argument against impeachment for sex-related offenses is obvious to anyone who lived through the late 1990s, and Democratic leaders will be cautious about overreach.

Not that it will matter much to Trump, who, as always, will be keen to fight back. And he just might win.